Efeito de diferentes níveis protéicos e do ácido linoléico conjugado no desempenho, custos de produção e qualidade de carne de frangos de corte

Abstract

initial, were allocated in accordance to a completely randomized design, with factorial model 3x3, corresponding in 3 CLA inclusion's levels (0%, 0,5% and 1,0%) and 3 CP's levels (19%,17%,15%). Weight gain reduction and increased feed conversion were only related to decrease of CP inclusion and both of factors, CP and CLA inclusion levels, elevated the economic index parameters.Carcass and breast meat yields decreased due to the reduction of CP addition in diets. The interaction between CLA and CP factors modified in liver size, and both elevated the abdominal fat percents. In relation to parameters analyzed in breast samples, the pH elevated proportionally to CP inclusion, the redness and yellowness were modified by CP or CLA addition and interaction of both were detected to luminosity parameter. About fatty acid composition, the addition of CP only elevated the stearic acid and CLA inclusion improved the saturated fatty acid levels and reduced the monounsaturated fatty acid levels. An improvement on incorporation of CLA isomers was verified due to more inclusion of this product in 19% or 17% CPs diets. In the case of 15% CPs diets, the incorporation of CLA isomers had a maxim limit. In the second assay, using 144 Ross line broilers with the same design and model, a quadratic effect for nitrogen balance was verified due to CP diets and an effect of interaction between CLA and CP inclusion was found to digestibility of dietary CP.